Journal Of Asian Earth Sciences: X 

About: Journal Of Asian Earth Sciences: X is an academic journal published by Elsevier BV. The journal publishes majorly in the area(s): Geology & Structural basin. It has an ISSN identifier of 2590-0560. It is also open access. Over the lifetime, 38 publications have been published receiving 26 citations.

Hydrogeochemical characteristics and groundwater quality investigation along the basinal cross-section of Pravara River, Maharashtra, India

Abstract: • Along cross-section area EC, Ca 2+ , Mg 2+ and HCO 3 − were found above BIS standards. • Hydrogeochemical faces found Ca 2+ -Cl − and Mg 2+ -HCO 3 − type along cross-section. • High salinity hazard was inferred at all sampling locations of river cross-section. • WQI and Wilcox diagram shows effluent discharge sites are more contaminated. • Groundwater in cross-sectional aquifer influenced by natural and man-induced causes. The groundwater samples collected along the cross-section of Pravara river basin is quite distinct in terms of geo-hydrologic and anthropogenic situation. Innovative methods were used to investigate hydrogeochemical phases and groundwater quality for which 33 groundwater samples collected and analysed for pH (7.6–8.7), EC (311–1851 μS/cm), TDS (306–1990 mg/l), Na + (11–296 mg/l), K + (0.6–2.2 mg/l), Ca 2+ (90–2001 mg/l), Mg 2+ (1–17.9 mg/l), Cl − (71–1036 mg/l), SO 4 2− (17–118 mg/l), NO 3 − (5.1–14 mg/l), CO 3 2− (14.4–40.8 mg/l), HCO 3 − (117–698 mg/l) and F − (0.05–1.34 mg/l). The water quality was inferred with the help of water quality index (WQI) and Wilcox diagram. Fluid properties and irrigation water characteristics, as well as ion balance and Piper diagram were coupled to explore the type of water. Resourcesat-2 satellite image was processed to know the land use land cover (LULC) of area and its effect on groundwater. The results of pH, K + , Ca 2+ , Mg 2+ , SO 4 2− , and NO 3 − were found within the prescribed limit. According to WQI, total 10 samples on RS and 09 samples on LS were found to have excellent quality water (57.58%) and 04 samples on RS and 05 samples on LS are good water (27.27%). The resulting Wilcox diagram also classifies the groundwater as excellent to good and good to permissible. The hydrochemical facies found Ca 2+ -Cl − type along RS and Mg 2+ -HCO 3 − type along LS. Based on hydrogeochemical characteristics and groundwater quality, the cross sectional aquifer is inferred to be predominantly influenced by natural as well as man induced causes, which have been validated by LULC results.

Morphological Response of the Pussur River, Bangladesh to Modern-Day Dredging: Implications for Navigability

Abstract: Mongla Port is the second gateway of Bangladesh, situated at the bank of the Pussur River some 131 km upstream from the Bay of Bengal. In this study, the available hydrographic survey charts of Pussur River were collected from Mongla Port Authority (MPA) and analyzed to assess the trends of morphological changes at the potential sites. The causes of navigation problems, previous interventions of MPA, dredging history of the river, and effectiveness of dredging was analyzed. It is found that in the upstream portion of the navigation route at the MPA jetty area and its approaches was slightly scour-prone from 2010 to 2013; however, after capital dredging in 2014, the channel was found highly siltation-prone, having a rate of 0.1–0.6 m/year between 2015 and 2017. Before dredging the channel, the Inner bar area (downstream of Mongla Port) did not show any significant change in the bed topography between 2010 and 2013, however, a high backfilling rate (up to 1.5 m/year) was observed after the capital dredging. The channel was sufficiently deep and quite stable from Joymonirgol to Hiron point. The current navigational channel at the outer bar (at the mouth of the river) is silted by 0.1–0.25 m/year. Reduction of upstream flow, numerous shipwrecks at different positions, and human disturbances were identified as the causes behind the navigational problems in the river route.

Consecutive statistical evaluation framework for earthquake forecasting: Evaluating satellite surface temperature anomaly detection methods

Abstract: Short-term earthquake prediction remains a challenge. In this study, we investigated earthquake predictability using a consecutive statistical evaluation framework (CSEF). Two widely used anomaly detection methods—Z-score (ZS) and Robust Satellite Techniques (RST)—were evaluated using the Atmospheric Infrared Sounder surface temperature data based on global M ≥ 6 earthquakes with focal depths of ≤70 km from 2006 to 2020. Retrospective correlation analyses reveal accuracy and missed detection rates of 80.33% & 19.67% and 80.93% & 19.67% for ZS and RST, respectively. For earthquake forecasting performance in seismically active regions, accuracy rates are within 0–1% and false alarm rates are up to 50–80%. Areas near earthquake-prone regions have the highest accuracy rates. The accuracy rates can be >10% within some regions in Japan and Indonesia. Overall temporal average Matthews correlation coefficients (MCC) range from −0.48 to 0.21; global spatial average MCCs for each day from 2006 to 2020 are between −0.1 and 0.1. After 2012, the ZS method yields higher MCC values than the RST method. Our results confirm the reliability of CESF for assessment of earthquake forecasting capability, and the possibility of forecasting earthquakes at earthquake-prone areas. This approach can be applied to long-term analyses of precursory parameters, anomaly detection methods, and hypotheses, all of which are essential to the ultimate goal of routine and consistent earthquake forecasting.

Study of hydrochemical and geochemical characteristics and solute fluxes in Upper Ganga Basin, India

Abstract: • COD and TSS exceeded the prescribed criteria limit for drinking purpose. • HCO 3 and SO 4 were observed as the dominant anions. • Peculiar behaviour of SO 4 was observed along the River Bhagirathi. • Significant correlation observed between flux and river discharge in Bhagirathi. Himalayan rivers are considered the most sensitive of all the ecosystems to the impact of climate change. In the present investigation, hydrochemical processes controlling the meltwater chemistry of the rivers Bhagirathi, Alaknanda and Ganga in the Upper Ganga Basin, India have been studied simultaneously creating a large database for the first time. For this purpose, an extensive water quality assessment in Upper Ganga Basin has been carried out by collecting water samples from all three rivers on monthly basis from September 2016 to May 2018 and analysing these samples for hydro-chemical parameters. Hydro-chemical characteristics revealed that sulphide oxidation and carbonation- the two proton producing reactions govern the chemical weathering processes pertaining in the rivers. One of the most peculiar findings of the study is the dominance of carbonate dissolution in the whole stretch of River Alaknanda, while the dominance of sulphide oxidation in River Bhagirathi upto Dabrani revealing the continuum of Gangotri glacial processes followed by carbonate dissolution upto Haridwar. The principalcomponent analysis further supports this weathering processin the basin.

A GIS-based assessment of active tectonics from morphometric parameters and geomorphic indices of Assam Region, India

Abstract: Assam region is mainly formed by the deposit and erosion process of the Brahmaputra River. The frequency of seismic events results in landform deformation, which highly influences the drainage basin pattern and causes drainage anomalies, having a subsequent effect on the flood distribution pattern. In the present study, morphometric parameters and geomorphic indices for the Assam region are derived from SRTM DEM data of 30 m resolution using GIS to characterize the tectonic activity, which in turn influences the drainage pattern. The indices are classified into three tectonic activity classes, and the average of the classes is combined to generate the indices of relative active tectonics (IRAT). The four classes of IRAT are defined for the study area as (i) very high; Class 1 (1.57–1.80), (ii) high; Class 2 (1.81–2.06), (iii) moderate; Class 3 (2.07–2.26), and (iv) low; Class 4 (2.27–2.30). Class 1 corresponds to basins 1 and 6. Basins 2, 4, and 5 fall under Class 2. Class 3 consists of basins 7, 8, and 9, and Class 4 comprises basins 3 and 10. Results show that most of the study area lies in very high to moderate active tectonic zones and the identified zones are consistent with significant faults and thrusts present in the basins. The combined approach of GIS-based morphometric and geomorphic study allows for identifying deformed landforms resulting from active tectonics. The results can also be employed for the development of watershed management and sustainable land use planning.